The present invention relates generally to manufacturing ceramic transducers and in particular to a technique for reducing mechanical failure and improving uniformity of lead zirconate-lead titanate (PZT) ceramic transducers.
A primary application for these transducers is in sonar and as a result these transducers experience fluctuating compressive pressures up to 20,000 psi under average conditions and up to 30,000 psi tensile stress under shock conditions. Presently the hoop tensile strength of PZT ceramic transducers vary 2000-5000 psi so that a quantity of these transducers may physically fail after a short time of use. Another major difficulty with the use of these ceramics is the lack of stability of electro-elastic properties with time and electric field. Consequently PZT transducers require replacement after approximately 1-3 years.
Previous attempts at producing a transducer material with greater and more uniform physical strength adversely affected the small signal dielectric and piezoelectric properties and the high field dielectric properties. However, these previous attempts generally entailed changing the composition of the transducer.